1. Field of the Invention
The present invention relates to archery weapons, and particularly to a projectile launcher provided with covered, internalized bow elements and corresponding cocking mechanism for increased balance, safe handling, and minimized effort in operation.
2. Description of the Related Art
Crossbows have long been known in the art. The traditional design dates back to the 14th century or earlier, when very high powered crossbows were effective, especially against armored horsemen. A large medieval crossbow of circa 1500 A.D. might have a draw weight of 1200 pounds and a range of 450 yards. In modern times, crossbows rarely exceed 200 pounds draw weight. Modern crossbows now use sighting mechanisms of various sorts, advanced composite materials and metal alloys, wheel/pulley systems, etc., but otherwise are little changed, except in style and construction materials. Draw weights are dramatically lower, which are tailored to target shooting or hunting applications, rather than warfare.
Crossbows normally use rifle-style stocks. Indeed, the modern rifle design originated with the medieval crossbow. Sights may be aperture sights, as found on a rifle; pin sights, as on a compound longbow; or telescopic sights. A modern 200 pound draw weight heavyweight crossbow will achieve similar projectile speeds to a 60 pound peak draw weight compound hand bow, and the bolt and arrow weights are also similar (300-400 grains).
The crossbow, being relatively short as compared to recurve bows and the like, requires comparatively more force to bend. Most crossbows must be cocked by using the feet and legs or a mechanical aid for very powerful bows. Because of the large amount of force applied and mechanical energy stored and released, significant safety concerns exist due to the structure of a conventional crossbow.
The bowstring sweeps along the top of the bow, and it is external. The bow limbs extend out to the sides of the crossbow and sweep forward when fired. The bolt travels openly exposed down the rail at high speeds when fired. Consequently, the user must exercise caution when cocking and uncocking, handling a cocked bow (whether loaded or unloaded), and firing to avoid inadvertent bodily contact with high energy and sharpened bow components. For example, the user must always take into account the sweep of the limbs when firing to prevent limb contact with external objects, which can cause significant back force into the stock and ultimately to the user's body (often the facial area). The user must avoid putting fingers/hands between the cocked bow and the bowstring.
The traditional crossbow, with its exposed mechanism and bowstring cocking mechanism, is not a compact design, which presents some ease of use concerns when applied to hunting applications as compared to a firearm/gun, and even the typical longbows and the like. The large cross-sectional area created by the bow limbs being mounted transverse to the stock can result in frequent snagging with tree limbs and foliage when being transported in the field. Mitigating the safety concerns described above often results in limited shooting angles when hunting in close proximity to trees due to the need for accommodating a “safe zone” around the bow limbs. The use of external (to the bow) cocking mechanisms that must be attached to the bow each time it is cocked or uncocked and that rely upon the physical strength of the user to perform these actions can often result in cumbersome and strenuous manipulations of the bow and associated equipment in a hunting scenario due to limited space.
The use of the cross-mounted bow and string also introduce potential shooting inaccuracy. Unless the bow is exactly evenly cocked such that the bowstring center point is being held by the trigger mechanism, side forces will be imparted on the bolt during acceleration down the rail, which will adversely affect its flight accuracy. Cocking the bow even 1/16″ off center will drastically change the bolt's point of impact.
Accurate aiming with crossbows is also adversely affected by their typical design. The conventional crossbow has an imbalanced weight distribution, which places the center of mass far forward of the weapon, due to the bow limbs and associated mounting placed at the distal end of the rail or table. Thus, the user must compensate and support the weighty forward end with more strength and care during aiming compared to typical firearms, such as rifles or the conventional recurve bow. One attempt to address this issue places the mounting hardware near the rear of the elongate table, and the bow limbs are mounted in reverse orientation from traditional, i.e., the arch of the bow faces the user instead of away from the user. This type of crossbow may provide better balance, but it still experiences the same type of concerns mentioned above, i.e., safety and the need to accommodate the cross-extending bow limbs during use.
Another concern of traditional crossbow designs arises from the results of a completed shot. The sudden dissipation of energy at the end of a shot through various components of the crossbow can cause excessive vibration in the bowstring, resulting in noise akin to a plucked guitar string. Since hunting requires a degree of stealth, anything compromising this aspect, such as the noise from a loosed bowstring, is highly undesirable. One solution includes dampener accessories mounted to the bowstring or bow assembly. While such accessories may assist in reducing the vibrations, they are one of many accessories that the user must consider. Depending on the size and complexity of such dampeners, they can negatively impact mobility and the space required for hunting, as well as projectile performance.
Several solutions have been proposed in my previous U.S. Pat. Nos. 8,486,170, 8,863,732, and 9,052,154, which are all hereby incorporated by reference in their entirety. The projectile launchers taught by these references eliminate or substantially reduce some of the known issues of conventional crossbows by providing a cross-bow type weapon that is balanced, safe handling, and easy and quiet to operate for increased convenience and stealth. There is still a need in the art of archery weapons, however, to provide a crossbow-type weapon that is relatively less complex and more energy efficient. Thus, a projectile launcher solving the aforementioned problems is desired.